The operation of an antenna is influenced by the arrangement of conductive elements in its vicinity and the performances of some antennas, such as planar inverted F antennas, are improved by using a conductive ground plane.
In a single part radio apparatus, optimal performance of the antenna may beachieved by adjusting the ground plane, for example, by adjusting its dimensions. For example, the optimal length of ground plane for operation at EGSM900 is of the order of 10 cm.
A multipart radio apparatus may have a ground plane formed from a combination of a conductive element in one part and a conductive element in another part. The separation of the ground plane into two interconnected parts typically makes the length of the ground plane too long or of indeterminate length as each part typically needs to have a length greater than 5 cm to be usable and the interconnection adds to the length in an unquantified manner.
It would be desirable to optimise performance of an antenna in a multi-part apparatus.